Nonadherence to medications is common and associated with poor or limited clinical outcomes in the treatment of bipolar disorder. A review of the literature discloses that adverse effects are one of the commonly reported reasons for nonadherence to mood stabilizers by patients with bipolar disorder. Nevertheless, other than such broad summaries, relatively little attention has been given to the role of adverse effects in relation to nonadherence. This review article is the first to consolidate the available data on this topic. Weight gain, perceived cognitive impairment, tremors, and sedation are the adverse effects most likely to lead to nonadherence. Further research is needed to anticipate, identify, manage, and potentially minimize the impact of adverse effects.